Ischemic strokes are the most common type of stroke, accounting for 83 percent of all strokes, according to Everyday Health. Normally, an ischemic stroke is caused by a blood clot that is formed from cholesterol and fats. When oxygen cannot reach areas of the brain, a stroke occurs.
There are two kinds of ischemic strokes, notes Everyday Health. A thrombotic stroke occurs when a clot forms in a blood vessel in the brain. An embolic stroke occurs when a blood clot forms somewhere else in the body. The clot then travels to the brain and becomes lodged in a narrow blood vessel, which results in a blockage.